for (SchemaColumn col : m_outputSchema.getColumns())
{
// At this point, they'd better all be TVEs.
assert(col.getExpression() instanceof TupleValueExpression);
TupleValueExpression tve = (TupleValueExpression)col.getExpression();
int index = tve.resolveColumnIndexesUsingSchema(input_schema);
tve.setColumnIndex(index);
}
m_outputSchema.sortByTveIndex();
// Find the proper index for the sort columns. Not quite